Sectional metallic centering-form.



APPLICATION FILED SEPT. 18. 1909.

Patented July 12, 1910.

Z SHEETS-SHEET 1.

WITNESSES:

INVENTOR W ATTORN EY H. BESSER. I SBOTIONAL METALLIC UENTERING FORM.

APPLICATION FILED SEPTJB, 1909.

Patented July 12, 1910.

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ing of the concrete,

HERMAN BESSER, 0F ALPENA, MICHIGAN.

SECTIONAL METALLIC CENTERING-FORM.

Specification of Letters Patent.

Patented July 12, 1910.

Application filed September 18, 1909. Serial No. 518,334.

To all whom 'it may concern:

Be it known that I, HERMAN BESSER, a citizen of the United States,residing at Alpena, in the county of Alpena and State of Michigan, haveinvented certain new and useful Improvements in Sectional MetallicCentering-Forms; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to sectional metallic centering forms for theconstruction of inonolithic sewers, conduits, culverts and the ike.

One object is the provision of a form of the character which can beplaced as a whole in the trench, surrounded with plastic material ascement, and then removed before the concrete surrounding the form hasbecome dry.

Another object is the provision of sectional forms adapted to bearranged in series, the sections of the form first placed adapted to betaken out and removed through the remaining elements of the series offorms with ease and despatch.

Still another object is the provision of means for removably securingthe individual members of the series of forms together, whereby theforms constitute a sectional cylinder of any given length.

A still further object is the provision of locking means for releasablylocking the sections of each form rigidly together and in perfectalinement, whereby they cannot sag out of shape.

By means of my invention, I am enabled to lay sewers, conduits and thelike without having to leave any considerable amount of open trenchahead or behind. The operation of constructing sewers, conduits,culverts and the like is continuous. The placthe setting up and takingdown of the forms, and the digging of the trench can all be proceededwith simultaneously, nor does one step have to wait for the other.

To these and other ends, therefore, my invention .consists in certainnovel features and combinations such as will be more fully describedhereinafter and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a perspective view showing thecomplete form joined to an incomplete form, the whole constructed inaccordance with my invention, Fig. 2 is a cross-sectional view on linem0a of Fig. l, the thickness of the shell being exaggerated for sake ofclearness, Fig. 3 is an end view showing the employment of tie bars onthe end form of a series, Fig. 4 is a detail view of one form offastening means for connecting the individual members of a series offorms, and Fig. 5 is a detail view illustrating one form of releasablelocking means for retaining the sections of a form in position.

Heretofore in laying monolithic sewers and like structures, it has beenthe practice to first place the lower half or invert of a form inposition and after the material surrounding such lower half has set,place there on the upper half or crown and surround that with plasticmaterial as concrete. Such independent sectional forms are, as a rule,strengthened or braced so that when the complete form is set up, theinterior or bore thereof is obstructed by braces, cross-supports and thelike. Furthermore, it is necessary to dig a trench of considerablelength which is kept open for a long time, disfiguring the street andofttimes rendering it impassable. Furthermore, in using forms of thischaracter, it is necessary that a large amount of blocking and rollersbe provided for bringing the sections ahead, nor is it possible toremove the forms first placed in position, until the materialsurrounding the entire series of forms has hardened. Thus, it isnecessary for the operator, after laying a section of the sewer, to waituntil that portion of the section last laid has hardened before removingthe forms because, under this method, the forms last laid are the formsfirst removed. Obviously, this necessitates the provision of a largenumber of forms which are not continuously used.

One advantage resulting from my invention is that with my forms, theform first laid is the form first removed and such form can be knockeddown, drawn through the forms last placed in position, and set up again,as soon as the concrete surrounding the first form has attained itsinitial set. By this means it is obvious that only a comparatively smallnumber of forms is necessary in building sewers and the like inaccordance with my invention, the open trench can be more quickly filledin and indeed, as

a .matter of fact, the crew is kept close together, better results areobtained from their labor, and the forms can be placed in position toreceive the concrete as fast as five or siX feet of open trench is made.

Referring to the drawings, 1, 1, 1 inclicate a plurality of segmentalsections adapted to be assembled to constitute a sectional form which ispreferably cylindrical in cross-section as shown. In the drawings, Ihave shown such form as consisting of four separable sections, it beingobvious that a smaller or greater number of sections may be used toconstitute a form, although in practice, I would not use less than threesections.

As one means for releasably securing the sections together to make theform, I provide one longitudinal edge of each section with an angle bar2, the flange 3 of which projects beyond the edge of the section onwhich the angle bar is secured. This angle bar 2 is secured to the innerface of the section, its projecting flange 3 being adapted to overlapthe inner face of the'neXt adjacent section. The opposite longitudinaledge of each of the sections 1, 1, 1, 1, is provided with a strap 4:having an offset lip 5, between which and the inner face of the sectionis received the overlapping flange 3 of the angle bar on thelongitudinal edge of the next adjacent section. It will be noticed thatthe edges of the sections 1,1,1 squarely abut each other and the lockingmeans above described, while simple, is very efficient and serves tointerlock the sections rigidly together in perfect alinement to preventthe sections from sagging relative to each other. One section 1 of eachform is provided with a turn button 6 pivoted securely to the inner facethereof in place of the lip 5, such turn button adapted to overlap theflange 3 of the angle bar 2 on the section next adjacent thereto, toenable the sections to be disassembled when desired. In setting uptheform, the section 1 is the last section to be placed in position and intaking down the form, all that is necessary is to swing the turn button6 on its pivot until its outer end releases the fiange 3 on the sectionnext adjacent thereto, whereupon the bottom section 1 may be swunginward on the point X as a pivot, after which the remaining sections areeasily drawn inward to disassemble the form.

As one means for maintaining a series of the forms in alinement, Iprovide the opposite ends of each section with angle bars 7, theradially extending flanges 8, 8, of which are apertured as at 9. Thesesegmental flan es 8, 8, are located at the opposite ends of tierespective forms and are adapted to abut similar flanges carried by theends of adjacent forms, in such manner that the apertures 9, 9 willregister, such apertures adapted to receive the pins 10 held in place inany suitable manner as by means of the wedge-shaped cross keys 11.

In disassembling one form relative to the adjacent forms, it is firstnecessary to remove the cross keys l1 and the pins 10, before thesections composing the form are swung inward.

Then the end of the trench is reached, or when leaving the forms inplace over night, it is desirable that the sections constituting the endform be held rigidly in position, to which end I have provided the chordbars 12, 12, extending between the adjacent sections and secured inplace in any convenient manner as by means of the pins 10 and cross keys11, such chord bars connecting the respective sections against relativemovement.

An inspection of Fig. 1 will show that the successive forms break jointsrelative to each other, whereby a stronger and more compact and firmconstruction results.

In taking down the forms, the sections are not sprung but are merelytaken apart, thereby saving much time and labor and retaining the formsalways in shape.

It will also be seen that the interior or bore of the forms is notobstructed but is left entirely open for passage back and forth, andshould a heavy rain flood into the forms, no obstruction to the passageof the water would be afforded to cause it to dam up.

The operation of my device may be briefly described as follows: l/Vhen asuficient length of trench has been dug, a bed of plastic material maybe laid in the bottom of the trench and the forms set up or placed inassembled position on the bed, after which the form is covered orinclosed by plastic material. If desired, earth can be filled in alongthe walls of the trench as the plastic material is laid up on both sidesof the forms, thus filling in the trench. As the length of the trenchincreases, additional forms are placed therein as above described, 110the adjacent ends of the forms being releasably connected. This processis continued, the trench being excavated as needed, so that onlycomparatively few feet of trench are open at one time. When the plas-115 tic material around the form first placed in position has becomesufficiently hard, the workman crawls through the forms subsequentlylaid, and releases the turn button on section 1 of the form first laid,swinging 120 such section inward until it is released from the remainingsections of the first form, after which such remaining sections may beremoved inwardly and drawn through the series of subsequently laid formsuntil the open portion of the trench is reached, whereupon thedisassembled form is set up in osition with its end adjacent the end ofthe orm last placed.

From the foregoing it will be seen that I 130 have devised a continuousmethod of building monolithic structures as tunnels, sewers and thelike, with economy, as a large number of molds are unnecessary.

To set up a form constructed in accordance with my invention, theflanges along the longitudinal edges of the sections are insertedbeneath the offset lips of the straps on the next adjacent section, thefinal sec tion l being placed in position and the turn button 6 rotatedso as to overlap the longitudinal extending flanges of the adjacentsection, thus completing the form and preventing its disengagement. Thesections cannot slide endwise relative to each other, on account of theend flanges 8, which lie in the paths of movement of the flanges 3 onthe successive adjacent sections.

It is evident that changes might be made in the form and arrangement ofthe several parts described without departing from the spirit and scopeof my invention.

Having thus fully disclosed my invention, what I claim as new, is

1. A centering form comprising a plurality of separable segmentalsections; an angle bar secured to one inner longitudinal edge of eachsection, the projecting flange of said angle bar overlapping the inneredge of the next adjacent section; a plurality of straps,

each formed with an ofiiset lip, said straps secured to the remaininglongitudinal edge of each section; a turn button secured to the innerface of one of said sections and adapted to overlap the flange of theangle bar of the next adjacent section.

2. A centering form comprising a plural ity of separable segmentalsections; an angle bar secured to one inner longitudinal edge of eachsection, the projecting flange of said angle bar overlapping the inneredge of the next adjacent section; a plurality of straps, each formedwith an offset lip, said straps secured to the remaining longitudinaledge of each section; a turn button secured to the inner face of one ofsaid sections and adapted to overlap the flange of the angle bar of thenext adjacent section, together with segment-shaped angle bars securedto the opposite ends of each section, said angle bars arranged with oneflange radial, said radial flange being apertured, and securing pinsreceived in said apertures.

In testimony whereof, I aflix my signature in presence of two witnesses.

Witnesses IDA MIDDAUGH,

WV. R. MCPI-IEE.

